Improved smeltina-purnace



@sind gisten @anni -1 dtjijiw.

Letters Patent No. 90,228, dated May 18, 1869.

IICPRO'VED SMELTmG-FURNACE.

The Schedule referred to in these Letten Patent and making part c( thelune.

To all whom it may concern Figure 2, a horizontal section -of the same,takenv on line :c fc, igfl.

Figure 3, a transverse section, taken on the line z z,Y fig. 4.

Figure 4, a longitudinal elevation.

The present invention relats to an improvement in the construction ofthat class of furnaces which is designed more especially for melting theprecious metals, and thereby separating them from pulverized quartz,silica, 85o.; and

. Its nature consists in the peculiar form of the arch,

-' smelting-pan, and their arrangement relative to the other parts, ashereinafter fully described.

A represents a easement, which is either made of brick, or othersuitable material, rmly clamped together by means of bands of iron, P P,85o.

In one end of the easement is arranged a fire-box, S, which has theordinary grates J, figs. l and 2, for a bottom, placed in such positionas to allow ashes to be removed by means or" an opening, K, and ablastpipe, I, to be placed below it.

The`casement A, surrounding the lire-box, is protected from the intenseheat that it would' otherwise be subjected to, by concrete, as shown atB B S', made of any' well-known substance used for a like purpose.

A smelting-pan, consisting of a metal outside, L, and a concrete lining,E, is fitted closely into the case A, and its upper edge is so coveredwith concrete,

which overlaps the inner wall B of the fire-box, as to fit closelyagainst an arched cap, G.

This cap has a peculiar form, as shown inthe drawings, being eoncave atthe under side, and convex at the top, the concave part terminating in aue, W, at

Aone end., for the escape of smoke, as shown at figs. 1

and 3. y

The `object of makingthe cap in this form is to provide a largeheating-chamber in the region of the pan E L, and at the same time bringtbe heat down as closely as possible to the pau before it escapes.

It will be seen from this description that the smelting is done by meansof bringing the heat directly over the top of the ore, instead ofbringing it underneath the smelting-receptacle, as is generally done.

By means of this construction and arrangement, an operator is enabled todraw oi the metal from the pan, through a hole, F, made for thispurpose, an open space, G, being left in the easement A, for theconvenience of placing a mould or kettle under the hole F, to receivethe molten metal as it flows out.

For large furnaces, the cap O will necessarily have to be made offire-brick, well cementedtogether, and

so laid as to have the joints tight, one end of the arch resting on tbelining of the tire-chamber, and the sides on shoulders at the sides ofthe pan, and projecting on to its edges N, as shown at igs. 1 and 3.

v When, however, the furnace is small, the cap C can be cast fromfire-brick clay, properly burned, and then placed in position, similartothe one shown'.

In either event, a'hole, D, should be made through the top, to supplythe pan with ore, or crushed rock,

as the case may be, and one or more openings, H, on each side, for theconvenience of working ofi' charges.

The operation is lquite simple, requiring only that the ore be put intothe pan, by means of the hole D and then subjected to -such heat fromthefire-box S as is necessary to melt the metal therein, taking theprecaution to close the holes H D, during the heating-process, withclay, or other material used for a like purpose. 4

The blast through the pipe I is produced in the usual manner.

When the cap is in one piece, it can be readily removed, for cleaningthe pan, repairing, &c.

Having thus fully described my invention,

What I claim, and desire to secure by Letters Patent of the UnitedStates, is

The peculiar construction of the cap O, when operated in combinationwith the easement A, lire-box S,

pan E L, as described.

RUDOLPH BOEHM. Witnesses;

FERD. WM. HERRMANN, G. L. OHAPIN.`

